The present invention relates to a marine riser system and a method of installing same and more particularly relates to a free-standing, marine riser for use in deep water areas to conduct fluids between the marine bottom and the surface.
A critical consideration in the production of hydrocarbons from marine deposits lies in providing a fluid communication system from the marine bottom to the surface once production has been established. Such a system, commonly called a production riser, is usually comprised of one or more conduits through which various, produced fluids are transported to and from the surface.
In many offshore production areas, a floating facility is commonly used as a production and/or storage platform. Since the facility is constantly exposed to surface conditions, it experiences a variety of movements, e.g., heave, roll, pitch, drift, etc. In order for a prduction riser system to adequately function with such a facility, it must be sufficiently compliant to compensate for such movements over long periods of operation without failure.
Also, as is commonly known, a zone of turbulence due to surface and near surface conditions exists just below the surface. For a riser system to have an acceptable operational life, it must also have sufficient compliance within this zone to compensate for the turbulence without interrupting the operation of the riser system.
Further, due to the water depths of some production areas, at least the lowermost elements of the riser system must be capable of being remotely installed without requiring any substantial assistance from divers. Likewise, the various elements of the riser system which undergo constant wear during operation, e.g., flowlines, must be capable of being removed individually for repair and/or replacement without requiring removal of the entire riser system. Finally, to provide for extremely hostile surface conditions, e.g., hurricanes, the riser must be capable of being quickly released from the floating facility and then being retrieved for reconnection once the surface conditions have subsided.